Variable Data Printing (VDP) is a form of printing that produces individualized printed pieces, each of which contain printed pages containing information targeted to an individual recipient. VDP authoring combines the graphical arts practice of graphical page authoring with Information Technology (IT) to provide utility to create variable data print jobs that will be input to one or more print production processes in which the printed and finished pieces are manufactured. The various variable content Instance Documents comprising a VDP Job are authored based on data drawn from a database containing records of information that characterizes the individual recipients. VDP is seen as having the potential to enable the high degree of one-to-one marketing communications for the graphic arts and printing industries as has been seen in one-to-one marketing practice using communication mediums such as the Internet.
A common problem that exists using VDP is that making print jobs using a variable data will typically take longer for a Raster Image Processor (RIP) to rasterize and print than a conventional static print job using non-variable data. Variable print data is sent to a RIP where code for text elements and graphic elements are processed into a raster data format that can be utilized by the marking engine of a digital printer. Therefore, every page having variable data must have each and every code element Raster Image Processed (RIPped). The necessity of having to individually RIP the elements having variable data creates a substantial processing bottleneck compared to RIPping static print jobs comprised of a single document which need only be RIPped once, and the many copies are imaged from the same RIPped result.
Beyond the conventional variable data printing practice of varying page content for respective Instance Documents, it is also possible to vary other characteristics of the printed pieces such as finishing characteristics including binding style, and substrate selection based on rules sensitive to the same recipient database information used in the conditional mapping of page content. In this way, for example, recipients of higher value to the marketing firm for which the VDP Job is produced, can receive a printed piece on a higher quality print media with a higher quality binding, whereas, their lower value customers with less value potential may only receive a corner stapled document that is less expensive to produce but has sufficient marketing impact to be noticed by the intended recipient. This implies the need to store along with the page content and layout data, additional data that expresses the physical characteristics of each piece to be manufactured known as product intent data. The addition of product intent data, which may vary the physical characteristics of the finished documents of the VDP job based on the data profile of the various recipients, may add significant complexity to the manufacturing process workflow in the print provider's environment where the required workflow may not be achievable. Hence, a significant problem exists where it is possible to author a VDP Job without knowledge of the print provider's manufacturing workflow capabilities that is too complex to be produced.
Accordingly, there is an ongoing desire within the graphic arts industry to correct the previously discussed shortcomings within the prior art and to enable a faster form of VDP up to final print production and finishing. It is also desirable to use currently practiced methodology within the print engine. The graphic arts industry needs both a method and an apparatus that can provide an efficient and reliable exchange of variable data for use in variable data print jobs.
A page definition mark up language, called Personalized Print Markup Language (PPML), developed by the Print On Demand Initiative (PODi) is an example of a data format that can represent the layout of the pages of the many unique Instance Documents of a variable data print job. PPML is based on the Extensible Markup Language (XML) and is structured in such a way that content data that is used multiple times under the same rendering context on one or more pages is explicitly identified so as to enable a consuming RIP process opportunities for improved processing performance. Ideally a PPML RIP would process all content elements, including both the identified reused and non-reused content elements, a single time where the re-used elements are stored in a cache after they are first RIPed and then reused as raster data.
Allowing a printer RIP to store and re-use rasterized graphic elements as needed provides a tremendous improvement in processing performance. The ability to re-use these elements also eliminates the need to resend the source code that defines the content element to the printer/RIP multiple times during the same print job. PPML is a significant advancement for variable data printing because it allows a printer/RIP to understand at an object level rather than a page level. It allows a printer/RIP to have a certain degree of intelligence and manipulate the components (objects) that make up a page. It also provides code developers the ability to name objects, which permits the re-use of the objects as needed during printing of a variable-data job.
Variable Data Exchange (VDX) is a standard that has recently been evolving within Committee for Graphic Arts Technologies Standards (CGATS), as a production tool for variable data in the form of a VDX instance combined with PPML. A VDX instance can be looked at as a compilation of records that define the content and layout of many composite pages. These VDX instances can be used with PPML to create the composite definitions of PPML/VDX Instance Documents. Each composite page of a PPML/VDX Instance Document is an assembly of one or more partial pages or content objects referred to as compound elements. PPML/VDX allows compound elements to be defined once and referenced many times from the various composite page layout instances to effectively reduce the overall size of data for a PPML/VDX instance.
The layout data that describes the composite pages of a PPML/VDX instance is defined using a subset of the previously described PPML. The data format required by the PPML/VDX standard for defining the compound element source data is the Adobe Portable Document Format (PDF) defined and maintained by Adobe Systems®. In PPML/VDX, the source PDL data that defines a compound element that is placed on a PPML defined page layout is always expressed as a page of a PDF file. PDF files used to define PPML/VDX compound elements must contain all the supporting resources such as fonts, image data, and color profiles. PDF files used to define PPML/VDX compound elements must also define all color content in a known reference device or device independent color-space.
VDX requires that the PPML layout data of a VDX instance be stored as a single, randomly accessible PDF object stream that is stored within a PDF file. Depending upon the conformance level, the PDF file embedding the PPML data may also contain some, or possibly all, of the PDF page object definitions required by the VDX instance that results in a PPML layout data object. The PPML/VDX file that has an XML element that contains the PPML and product intent data, referred to as the PPML/VDX Layout File. PDF files that contain only PDF page objects used only for defining compound element definitions and have no XML elements stored within them and may be referenced from the PPML data store in a PPML/VDX Layout file, these PDF files are referred to as a PPML/VDX Content File.
A completely specified device and production workflow independent VDP Job definition is comprised of three basic components, two of which define the appearance of the variable page content, namely layout (also referred to as mark-up) data, and content data. In a PPML/VDX instance, the layout component is defined by the PPML data, and the content component is defined by the PDF data. The third component, known as product intent data, provides the description of the finished product. The product intent data typically includes information such as document binding styles, single and/or two sided print options, substrate types, and other attributes of a print product description required for communicating to a print service provider the definition of the final print products that are to be manufactured. Product intent information does not define the controls of a particular target manufacturing process or device because such information is usually not known to the PPML/VDX authoring agent. These device control parameters are usually only known to the print provider who receives the exchanged VDP Job data. The print provider, therefore, must derive the manufacturing specifications specific to their production workflow or workflows from the product intent, layout, and content data specification created by their customer.
A PPML/VDX instance is created by a data driven merge process referred to as a variable data merge engine. The merge engine typically executes within an authoring environment for variable data. The authoring environment can be located at a different location from the graphic arts establishment that actually prints the final pages of the variable data documents. In some scenarios, a PPML/VDX instance may be sub-divided into several PPML/VDX instances that can be transferred to different locations to be printed. Generation of a PPML/VDX instance by the variable data merge engine is considered a final activity in the somewhat complex process for authoring variable data. The PPML/VDX instance can be transferred to a print production workflow within the same or different operating environment where it can be viewed by a prepress operator, and placed into a final production ready form that is suitable for the digital printer used at that location.
The PPML/VDX is a portable format that is expected to enable growth in the practice of variable data printing within the printing industry. PPML/VDX allows printers with dynamic digital printing capability to participate in variable printing without the need to acquire one-to-one marketing, variable layout design, or data processing expertise. However, PPML/VDX is strictly a final form variable data and layout format that is device independent. Therefore, PPML/VDX does not support the inclusion of data that is specific to a printing device such as imposition layout, trapping parameters, traps, or any printer or general device control information. Accordingly, data that contains specific information for a printing device needs to be added later during the prepress activity when the print job is being prepared for production.
From the foregoing discussion it should be apparent that there remains a need within the art for a method and apparatus that can supply printing device specific data to be used in conjunction with PPML/VDX instances to enable growth in variable data printing practice within the printing industry.